In 1973, the peer-reviewed journal Science published a now-classic study in psychology. In its introduction, the study’s author, D.L. Rosenhan, pointed out that the criteria for determining whether someone is mentally ill are highly subjective. The provocative question Rosenhan asked was this: Do diagnoses of mental illness come from the patient themself, or from the context in which a medical observer examines them? This study was designed to answer that question.

Rosenhan recruited eight normal, healthy individuals, whom he termed “pseudopatients”. Each of the pseudopatients arrived at one of a variety of mental hospitals and checked themselves in, claiming to be hearing voices saying words such as “empty”, “hollow”, and “thud”. Other than this fictitious symptom and the use of pseudonyms, they truthfully answered every question they were asked, and once they were admitted, they immediately stopped complaining of any symptoms at all. At all times, they remained polite and cooperated with the hospital staff (medication was surreptitiously flushed down the toilet). The objective of the study was to see how long it would take for the staff to realize that they were not mentally ill and release them.

The results were shocking. The pseudopatients were all released after between 7 and 52 days, with an average stay of 19 days. But more importantly, not a single one was realized to be sane by any of the doctors or nurses at any of the hospitals. Instead, they were released with diagnoses such as “schizophrenia in remission”. Even more bizarrely, the other patients were more likely to recognize the pseudopatients as normal than the hospital staff. 35 out of 118 genuine patients voiced suspicions about the pseudopatients’ claims of mental illness, and some told them, “You’re not crazy. You’re a journalist, or a professor! You’re checking up on the hospital.”

Even seemingly obvious clues were overlooked. The pseudopatients kept notes on their experience; at first they attempted to conceal these, but soon realized there was no need. Even when the doctors observed them writing, they dismissed it as “note-taking behavior”, another symptom of the presumed psychosis. When they asked ordinary questions such as, “Excuse me, doctor, can you tell me when I am likely to be discharged?”, the staff frequently answered with non sequiturs such as, “Hello, Dave. How are you today?” and then moved off without waiting for a response. In interviews, the patients related their life histories truthfully, which might seem to provide evidence against a diagnosis of mental illness since they were legitimately well. However, these histories were likewise twisted, with psychiatrists interpreting and labeling every drifting apart as “ambivalence”, every fight with loved ones as “outbursts of anger”. There was no evidence of any conscious distortion; the staff legitimately believed in the initial diagnosis, which became a lens that colored all their subsequent interpretation of the evidence. In a sense, the fact that the pseudopatient was in a mental hospital seemed to be all that was required for the doctors and nurses to conclude that they were insane and treat them accordingly. Once a diagnosis was made, it tended to “stick”, and from that moment on, the staff assumed that all behavior stemmed from that diagnosis.

Rosenhan’s paper spurred a variety of reforms in the mental-health industry, and it is to be hoped that the specific problems he identified have been, if not eliminated, at least lessened. But the ugly mark of presupposition has by no means been overcome, even today. This study was about conscious presuppositions, decisions made by doctors and nurses with the full consent of their faculty of reasoning. Chapter 3 of Malcolm Gladwell’s 2005 book Blink discusses a different kind of presupposition – an unconscious kind – that can be brought out by a simple psychological exam known as the Implicit Association Test. Test-takers are shown a list, with two categories, and are asked to place each item onto the list in its appropriate category as quickly as possible. For example, consider this list:

Male

Female

John

Bob

Amy

Holly

Joan

Derek

Most participants find this test easy. Now consider a minor modification, where each category consists of two possibilities:

Male or Career

Female or Family

Lisa

Matt

Laundry

Entrepreneur

John

Merchant

Housework

Though this test is more difficult, most test-takers still do fairly well on it, consistently answering in between four and six hundred milliseconds. But now, consider a subtle variation:

Male or Family

Female or Career

Lisa

Matt

Laundry

Entrepreneur

John

Merchant

Housework

When presented with this altered version, most participants – of both genders – score significantly worse, both taking longer to assign items (up to three hundred milliseconds longer, a huge margin in a test of this type). Evidently, whether on a conscious level or not, most people associate careers and business with men and housework and family with women. Though we can overcome these associations by an effort of will, it is considerably more difficult and requires more cognitive effort. Despite decades of feminist advocacy for women’s equality, despite laws and policies that combat gender discrimination, it seems that these prejudices have not been fully eradicated, even among the best of us.

Now consider the most unsettling implicit association test of all:

European-American or Good

African-American or Bad

Hurt

Evil

Glorious

Wonderful

European-American or Bad

African-American or Good

Hurt

Evil

Glorious

Wonderful

The results of this test are frightening: No matter what participants say about their attitude toward racial equality, a large majority – about 80% in general, and about half of African-American participants – take measurably longer when asked to link positive concepts with African-Americans than with Caucasians. Again, it seems that despite everything that has been said or written on the subject of racial equality, at some level the old biases persist. Even people who do not consciously harbor any racial prejudice, who would never in their lives dream of discriminating against another based on gender or skin color, are often not able to fully overcome it. From somewhere – and it is an open question from where these biases were learned – the vile memes are still being transmitted. (For those of you who want to test your own preconceptions, the Implicit Association Test can be taken online, at https://implicit.harvard.edu/implicit/demo/measureyourattitudes.html.)

Granted, whether any of these implicit associations translate into any measurable difference in our actual behavior has not been determined. But these results should still be deeply disturbing to any educated, tolerant individual: ugly, harmful presuppositions can take root despite our best efforts to eradicate them.

Together, these experiments show just how vulnerable the human mind is to this type of error. Information learned both consciously and unconsciously can seep in to bias our decisions without our being aware of it, and in spite of our attempts to correct for it. Even highly educated, tolerant people, the kind of people that would probably be considered least likely to hold presuppositions, can be vulnerable.

How then can we believe any of our positions to be reliable? Is the quest for knowledge hopelessly subjective? The next post in the Observatory will consider these important questions and suggest a solution.